Automated system for adding multiple fluids to a single container

ABSTRACT

A device is described for accurately transferring multiple individual fluids from multiple source containers into a single receiving container. Fluid flows from the multiple source containers through individual fluid conduits to a chamber having a single fluid outlet conduit. The fluid outlet conduit is in fluid communication with a single receiving container. A pressure conduit is in communication with the chamber for alternately creating positive and negative pressures in the chamber to cause fluid to flow from the individual source containers into the chamber, and to cause fluid flow from the chamber into the receiving container in response to commands from a controller.

This application is a continuation, of application Ser. No. 938,676,filed Dec. 5, 1986, abandoned.

BACKGROUND OF THE INVENTION

The invention generally relates to systems for transferring fluids fromindividual source containers to a receiving container, and morespecifically relates to systems for transferring liquid drugs fromindividual vials, bottles, or bags to a single solution bag or bottlefor administration to a patient.

In hospitals, it is frequently necessary to provide solutions forintravenous administration to a patient which contain a variety of drugsin a single solution container. A common example of such a need ariseswhen a patient is receiving all of his nutritional needs intravenously.In this situation, the patient will typically receive a basic solutioncontaining amino acids, dextrose, and fat emulsions which provide amajor portion of the patient's nutritional needs. However, this solutionis insufficient to maintain a patient for an extended period of time.Therefore, a typical total parenteral solution includes as many as eightto twelve additional additives. The additives are typically minutequantities of vitamins, minerals, electrolytes, etc. Therefore, when apharmacist is preparing a solution for total parenteral nutrition, it isnecessary for the pharmacist to individually add each of the additionaladditives to a solution container after the base solutions have beenadded. This is typically done with individual syringes and requires arelatively long time on the part of a pharmacist to accurately add eachof the required additives.

An atutomatic compounding device has been recently developed to assistthe pharmacist in preparing solutions for total parenteral nutrition.This device is described in U.S. Pats. Nos. 4,467,844 and 4,513,796which are incorporated herein by reference. This device is used toassist the pharmacist in automatically compounding the base solution ofamino acids, dextrose and fat emulsions. This system typically usesthree or more peristaltic pumps to individually pump each of the basesolutions from three or more separate source containers. Computersoftware also has been developed and is currently being used to programin the amount of solution required for a series of individual patients.This program is designed to operate the automated compounding equipmentdescribed in each of the above patents. This program is more fullydescribed in U.S. patent application Ser. No. 665,268 filed Oct. 26,1984 now U.S. Pat. No. 4,653,010, which is also incorporated herein byreference. While this system has provided a tremendous advantage to thepharmacist, it is not useful for adding minute quantities of fluidadditives to the receiving container. Therefore, a need exists for adevice which can very accurately dispense very small quantities offluids into a receiving container.

SUMMARY OF THE INVENTION

An object of the invention is to provide a device for dispensing verysmall quantities of fluids into a single receiving container.

Another object of the invention is to provide software for controllingthe device as described above.

Another object of the invention is to provide a device which uses asingle pump to dispense multiple fluids from multiple source containersinto a single receiving container.

Yet another object of the invention is to provide a system foraccurately controlling fluid flow in which fluids from multiplecontainers are transferred to an intermediate measuring chamber and thenlater automatically transferred to a receiving container.

Yet another object of the invention is to provide a means for creatingpositive and negative pressures in the measuring chamber described aboveto control fluid flow into and out of the chamber.

Another object of the invention is to provide an administration set fortransferring fluids from multiple source containers to a measuringchamber, and then from the measuring chamber to a single receivingcontainer.

Another object of the invention is to provide a device which accuratelyrecords and maintains records of the transfer of multiple fluids into asingle source container.

And yet another object of the invention is to provide a means forperiodically flushing the measuring chamber described above to rinse thechamber of any incompatible drugs.

The invention can be briefly described as a device for accuratelytransferring multiple individual fluids from multiple source containersinto a single receiving container. Fluid flows from the multiple sourcecontainers through individual fluid inlet conduits into a measuringchamber having a single fluid outlet conduit in fluid communication withthe single receiving container. The chamber also has a pressure conduit.A first occlusion means for selectively preventing fluid flow from eachof the individual fluid inlet conduits to the chamber is provided inaccordance with the invention. A pressure means or differential pressuresource for selectively creating positive and negative pressures in thechamber to control the rate of fluid flow through the chamber is alsoprovided. In order to control fluid flow from the chamber to thereceiving container, a second occlusion means for selectively occludingfluid flow from the chamber outlet fluid conduit to the receivingcontainer is provided.

Control means for controlling the first and second occlusion means andthe pressure means is provided to perform various functions. Forexample, the control means causes the first occlusion means to allowfluid to flow through at least one of the individual fluid conduitswhile causing the second occlusion means to prevent fluid flow into thereceiving container. The control means also simultaneously causes thepressure means to create a negative pressure in the chamber to preciselycontrol the amount and rate of fluid flow into the chamber. The controlmeans further causes the first occlusion means to prevent fluid flowthrough all of the individual fluid conduits after a predeterminedamount of fluid has been delivered to the chamber. The control meansthen further causes the second occlusion means to allow fluid to flowfrom the receiving chamber through the outlet conduit whilesimultaneously causing the pressure means to create a positive pressurein the chamber to force fluid from the chamber into the receivingcontainer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the device;

FIG. 2 is a plan view of a transfer set in accordance with the preferredembodiment of the subject invention;

FIG. 3 (a) is a perspective view of a coupler used in the transfer setof FIG. 2;

FIG. 3 (b) is a cross-sectional view of the coupler of FIG. 3(a) takenalong the line 3(b);

FIG. 4 is an exploded view of a pair of mating plates and its associatedtubing as used in the transfer set of FIG. 2;

FIGS. 5(a) and (b) are side and end views, respectively, of highlycompliant tubing used in the set of FIG. 2;

FIG. 6(a) is perspective view of a manifold of the transfer set of FIG.2;

FIG. 6(b) is a cross-sectional view of a manifold of the transfer set ofFIG. 2;

FIG. 7(a) is a perspective view of one embodiment of a chamber of thetransfer set of FIG. 2;

FIG. 7(b) is a cross-sectional view of a chamber of the transfer set ofFIG. 2;

FIG. 7(c) is a perspective view of one embodiment of a cap used with thechamber of the transfer set of FIG. 2;

FIG. 8 is a partially exploded perspective view of the first occlusionmeans of the device;

FIG. 9 is another exploded perspective view of the first occlusion meansof the device;

FIG. 10 is a perspective view of the pressure means for selectivelycreating positive and negative pressures in the chamber of FIGS. 7(a)-(c);

FIG. 11 is a perspective view of the tubing used in the pressure meansof FIG. 10 in conjunction with a peristaltic pump head and of an airventing means used in one embodiment of the invention;

FIG. 12 is a partially-broken away end view of a air relief valve of thepressure means of FIG. 10;

FIG. 13 is a top view of the base plate of the housing in the preferredembodiment of the invention;

FIG. 14 is a side view of the base plate of FIG. 13;

FIG. 15 is a perspective view of the second occlusion means of thedevice;

FIG. 16 is a partially exploded view of the mechanical design of theload cell assembly in the preferred embodiment of the invention;

FIG. 17 is a perspective view of the housing covering the load cell ofFIG. 16;

FIG. 18 is a side view of an individual source container hanger;

FIG. 19 is a rear view of the hanger of FIG. 18 without a sourcecontainer;

FIG. 20 is a cross-sectional view of a spring mechanism used in thepreferred embodiment of the invention;

FIG. 21 is an exploded perspective view of the spring mechanism of FIG.20;

FIG. 22 is an illustration of a keyboard entry device;

FIG. 23 is a simplified block diagram of a pair of microprocessors usedin the preferred embodiment of the invention;

FIG. 24 is a flow chart of a "power-up" routine of the preferredembodiment of the invention;

FIG. 25 is a flow chart illustrating the keyboard entry mode program;

FIG. 26 illustrates a display panel for displaying specific gravity andvolumetric information for each source container;

FIG. 27 illustrates a display panel for displaying status informationduring operation of the device;

FIGS. 28(a) and 28(b) are a flow chart illustrating a "pump control"routine of the referred embodiment of the invention;

FIGS. 29(a) and 29(b) are a flow chart illustrating a the "keyboardmonitoring routine" of the preferred embodiment of the subjectinvention;

FIG. 30 is a flow chart illustrating a "pump monitoring" routine of thepreferred embodiment of the invention;

FIG. 31 is a flow chart illustrating a "complete" routine of thepreferred embodiment of the invention;

FIG. 32 is a flow chart illustrating a "hold" routine used by a pumpingmicroprocessor in the preferred embodiment of the invention;

FIG. 33 is a block diagram of the electronics of a load-cell amplifierand A/D convertor of the preferred embodiment of the invention;

FIG. 34 is a flow chart illustrating a "pumping" routine used by apumping microprocessor in the preferred embodiment of the invention;

FIG. 35 is a flow chart illustrating a "fill" routine performed by thepumping microprocessor in the preferred embodiment of the invention;

FIG. 36 is a flow chart illustrating a "drain" routine performed by thepumping microprocessor in the preferred embodiment of the invention;

FIG. 37 is a flow chart illustrating a "rinse" routine performed by thepumping microprocessor in the preferred embodiment of the invention;

FIG. 38 is a flow chart illustrating a "pumping control" routine for themaster microprocessor; and

FIG. 39 is a flow chart illustrating a "master control" routine for themaster microprocessor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Description of theMechanical Features of the Device

A. Overview

In accordance with the invention, a device 10 (FIG. 1) is provided foraccurately transferring individual doses of separate fluids fromindividual source containers 12. Each individual source container maycontain a different fluid 14. In some cases, the fluid in one containermay be incompatible with fluids contained in other source containers.According to the invention, fluid is transferred from each sourcecontainer 12 through a separate individual fluid conduit 16 to a singlechamber 18. The chamber 18 is suspended from a load cell 20. The loadcell 20 constantly weighs the total weight of the chamber to develop anoutput signal which is indicative of the amount of fluid in the chamber18 at any given time.

The chamber 18 is provided with a single chamber fluid outlet conduit 22which is in fluid communication with a single receiving container 24. Inaccordance with the preferred embodiment of the invention, the receivingcontainer 24 may have been previously partially filled with a basesolution 25 typically consisting of amino acids, dextrose, and fatemulsions. However, it is not required that the receiving containercontain any fluid prior to operation of the device.

The chamber 18 also includes a pressure conduit 26 which is in contactwith a pressure means. In the preferred embodiment of the invention, thepressure means is a single peristaltic pump which will be discussed ingreater detail below. The purpose of the pressure means is toselectively create positive and negative pressures in the chamber 18during operation of the device to control the rate of fluid flow intoand out of the chamber.

The device is further provided with a first occlusion means 28 whichwill also be discussed in greater detail below. The purpose of the firstocclusion means is to selectively prevent fluid flow from each of theindividual fluid conduits 16 from entering the chamber 18 in the absenceof a command from a control means 32. During operation of the device inthe preferred mode of the invention, the first occlusion means 28 willonly allow fluid to flow from one source container 12 to the chamber 18at a time. In this manner, it is possible to very accurately monitor theamount of fluid flowing from each container into the chamber through theuse of load cell 20.

The device further includes a second occlusion means 30 for selectivelyoccluding fluid flow from the chamber outlet fluid conduit 22 to thereceiving container 24. In the preferred embodiment of the invention,the second occlusion means 30 is a solenoid occluder. This occluder willbe discussed in greater detail below.

The device is controlled by a control means 32 which controls the firstand second occlusion means as well as the pressure means. The controlmeans causes the first occlusion means to allow fluid flow through atleast one of the individual fluid conduits 16 while causing the secondocclusion means 30 to prevent fluid flow from the chamber 18 into thereceiving container. The control means enhances fluid flow into thechamber 18 by creating a negative pressure in the chamber, therebydrawing fluid from the source container 12 through the individualconduit line 16 into the chamber. After the load cell 20 has sensed thatthe appropriate amount of fluid has entered the chamber 18 from aparticular source container 12, the control means causes the firstocclusion means 28 to prevent further fluid flow from that sourcecontainer. At this point, the control means 32 may then either cause thefirst occlusion means 28 to allow fluid to flow from another sourcecontainer into the chamber, or cause the second occlusion means 30 opento allow fluid to flow from the chamber 18 into the receiving container24.

The control means may allow a second fluid to flow into the chamber whena first fluid is still present in the chamber if the first and secondfluids are compatible with each other and there is sufficient emptyspace remaining in the chamber to receive the entire amount of thesecond fluid to be dispensed. The control means will not allow a secondfluid to enter the chamber when a first fluid is still present if thetwo fluids are incompatible with each other, or if insufficient roomexists in the chamber.

The control means 32 enhances fluid flow from the chamber 18 into thereceiving container 24 by causing the pressure means to generate apositive pressure in pressure conduit 26 which is in fluid communicationwith the chamber 18. This causes a positive pressure in the chamber sothat when the second occlusion means 30 is opened to allow fluid to flowfrom the chamber to the receiving container 24, the positive pressurewill force the fluid out of the chamber and into the receiving container24. This greatly reduces fluid retention in the chamber 18.

B. Transfer Set

Referring now to FIG. 2, a transfer set 34 is described in greaterdetail. The purpose of the transfer set is to transfer fluids from eachof the individual containers 12 into the receiving container 24. As canbe seen in FIG. 2, the transfer set 34 includes a plurality ofindividual fluid conduits 16. Each of the individual fluid conduits isformed of a flexible piece of tubing. Various materials can be used tomake the flexible conduits such as polyvinylchloride (PVC) orpolyethylene tubing. Polyethylene tubing may be desired when the deviceis used with drugs that are incompatible with PVC. A proximal end ofeach of the individual conduits 16 is mounted in a tray 38. The purposeof the tray is to maintain each conduit 16 in a spaced-apartrelationship from the other conduits and to keep the tubes organizedwhen the transfer set is being mounted onto the device 10. In thepreferred embodiment, the tray is a vacuum-formed plastic tray made ofPVC or glyrol-modified polyethylene teraphthalate (PETG).

In the preferred embodiment of the invention, the tray is specificallydesigned so that the distal end 39 of each fluid conduit 16 ispositioned adjacent to the particular source container 12 to which thedistal end 39 of the conduit 16 is to be connected. Referring again toFIG. 1, the individual conduit 16 exits tray 38 in such a manner thathalf of the individual conduits 16 are directed to one side of thedevice 10, while the other half of the individual conduits are directeddownwardly to the other side of the device. Since the source containersin the preferred embodiment are disposed along both sides of the device10, this greatly assists the pharmacist in insuring that the appropriateindividual conduit 16 is connected to its respective container 12 whenthe transfer set is placed in the device 10.

In one embodiment of the invention, each of the individual conduits maybe color-coded with a stripe or other type of coding on the tubing toindicate the identity of a particular tube. In the preferred embodiment,each tube contains a vented spike 40 at the distal end. This spike 40 isused to provide fluid communication between the distal end of the tubing16 and an individual container 12. The purpose of providing a ventedspike 40 is to allow air to vent into the source container 12 as thefluid is being dispensed from the source container when the sourcecontainer is a rigid, nonvented vial. It is currently envisioned thatthe source containers will be formed of either glass or plastic vials,bottles, or bags. However, if flexible containers are used as the sourcecontainers, or if the vials are vented rigid vials, it is not necessaryto provide venting in the spike.

Referring once again to FIG. 2, the tray 38 contains a coupler 42. Theproximal end 41 of each fluid conduit 16 is attached to one side of thecoupler. Individual tubes 43 which are highly compliant are attached tothe other side of the coupler. The coupler is illustrated in greaterdetail in FIGS. 3 (a) and (b). As can be seen in the figures, thecoupler 42 includes a wall 44 which contains a first series of couplingconduits 46 extending from one side thereof and a second series ofcoupling conduits 48 extending from the other side of the wall 44. Eachof the first and second coupling conduits in the series is in fluidcommunication with one another so that when the distal end of each oneof the conduits 16 is fixed in fluid communication with one of the firstseries of conduits 46, and a proximal end of one of the highly compliantindividual tubes 43 is attached to one of the second series of conduits48, fluid communication is produced between conduit 16 and itsrespective highly compliant individual tube 43. While other methods ofproducing fluid communication between conduits 16 and individual tubes43 may be used in accordance with the invention, the coupler illustratedin FIGS. 3 (a) and (b) represents one system for attaching the twoportions of tubing to one another while maintaining the tubes in ahighly organized manner.

Referring once again to FIG. 2, as can be seen in the figure, the tray38 includes a first series of finger-like projections 50 which maintainthe compliant tubes in a spaced-apart relationship from one anotherimmediately adjacent the coupler 42. The compliant tubes 43 are thenpositioned in the tray such that they pass between an open section orwindow 52 in the tray. When the tray is mounted in the device 10, theopen section is in direct contact with the first occluder means 28 toprovide appropriate occlusion of the compliant tubes 43, as will bediscussed in greater detail below.

As can be seen in FIG. 2, the individual tubes 43 then pass through asecond series of finger-like projections 54 downstream from the window.The second series of finger-like projections also maintains the tubingin the appropriate position to ensure that occlusion of the appropriatetube occurs. As will be obvious to one skilled in the art based on theteachings herein, it is possible to provide a variety of systems formaintaining the tubing in the appropriate position.

One end of the tray 38 is provided with a mounting means or elbow 56 formaintaining the individual tubes 43 as the tubes exit the tray. Themounting means is specifically designed to position the tubes in anupwardly extending position to reduce mechanical stress effects on thetubes on the chamber 18. In other words, it is important that the tubes64 do not create a variable force on the chamber 18 which woulderroneously effect load-cell readings during operation of the device.This aspect of the invention will be discussed in greater detail below.

The mounting means 56 is more clearly described in FIG. 4. As can beseen in FIG. 4, the mounting means 56 in the preferred embodimentconsists of a pair of mating plates 58 and 60. Each of the platescontain parallel grooves to receive each of the individual tubes. One ofthe purposes of the grooves is to space the tubes more closely to oneanother and to direct the tubes in the upward position as describedabove. In the preferred embodiment of the invention, the individualtubes 43 can be extruded as a single piece as illustrated in FIGS. 5 (a)and (b). As can be seen in FIGS. 5 (a) and (b), all of the tubes 43 canbe formed as a unitary piece with relatively thin connecting portions 62connecting each tube to its adjacent tubes. After manufacture of thetubes using this technique, a first section 64 (FIG. 2) of the tubes canbe maintained as a unitary piece, while a second section 56 of the tubescan be individually split to form the individual tubes which are mountedbetween the coupling means 42 and the mating plates 56 so that they passthrough window 52.

As can be seen in FIG. 2, one end of the individual tubes 43 isconnected to a manifold 67 in the upper portion of chamber 18. Themanifold is shown in more detail in FIGS. 6 (a) and (b). As can be seenin FIG. 6(a), the manifold includes a series of connector conduits 68 towhich one end of each of the individual tubes 43 can be attached toprovide fluid communication between the individual fluid tubes and thechamber when the manifold is connected to the chamber. The manifold hasindividual, spaced-apart, drop-former structures for each line fordiscouraging accumulation of droplets on the manifold. This preventspossible mixing of incompatible solutions due to droplets hanging on themanifold. This also prevents measuring the weight of materials that werenot actually transferred into the container.

The manifold 67 can be disconnected from the chamber in the preferredembodiment of the invention. This feature of the invention allows theuser of the device to change chambers 18 after each patient withoutchanging the rest of the tubing in the transfer set. While it is notcurrently envisioned that it will be necessary to change the chamberafter preparing a solution for each individual patient, it mayoccasionally be desirable to use a new chamber whenever a highlyincompatible drug or a highly toxic drug has been dispensed using thisdevice. As can be seen in FIG. 6(b), the mechanism by which the manifoldis releasably engaged with the chamber includes a pair of latches 70.Each latch can be flexed to release the manifold 67 from a lockinggroove 72 in the top or cap 74 of the chamber 18, as illustrated in FIG.7 (c). In the preferred embodiment of the invention, the latch consistsof an arm 76 which is mounted on a frame 78 of the manifold. A flexibleconnecting portion 80 maintains the arm 76 in a parallel relationship toa portion of the frame 78 of the manifold. The latch 70 can be flexed sothat the arm 76 and the frame 78 are no longer parallel with one anotherto release the manifold from the cap 74 of the chamber.

In order to provide a temporary seal between the manifold and thechamber cap 74, in the preferred embodiment of the invention, an O-ring82 is provided around a groove 84 in the manifold. Typically, the O-ringis formed of silicone rubber or neoprine, however, other materials maybe used. The O-ring provides an air-tight seal between the manifold andthe cap during engagement of the manifold to the cap of the chamber.

C. Chamber

The chamber of the preferred embodiment is more clearly described inFIGS. 7(a), (b) and (c). As can be seen in FIG. 7(a), the chamber 18 hasa generally rectangular cross-sectional area in the preferredembodiment. The purpose providing a rectangular area for the chamber isto allow the body of the chamber to be placed as close as possible tothe device 10 when the transfer set 34 is loaded in the device. Thechamber is also designed to have downwardly sloping walls 80 from thetop of the chamber to the outlet conduit 22. This also helps absorbimpact on the load cell from the acceleration of the solution due togravity. The effective height for acceleration is reduced by the funnelshape. This also reduces splashing which means less need for a rinsecycle. This is to enhance fluid flow from the chamber through the outletconduit 22. As will be readily apparent to one skilled in the art, it ispossible to design chambers having other shapes.

The key features of the chamber include the fact that a pressure line 26(FIG. 1). is in communication with an upper portion of the chamber andthat a manifold 67 delivers individual fluids from each of theindividual fluid lines into the chamber through a separate fluid path.This means that any mxing of the fluids does not occur until the fluidenters the chamber. As discussed above, it is possible to prevent mixingof fluids in the chamber if desired by emptying the chamber after eachindividual fluid has entered the chamber.

D. Outlet Conduit

An outlet conduit 22 is in fluid communication with the lowermostportion of the chamber in the preferred embodiment of the invention.Referring again to FIG. 1, the secondary occlusion means 30 is providedin the preferred embodiment of the invention to prevent fluid flow fromthe chamber as the chamber is being filled. The secondary occlusionmeans 30 is described in greater detail in FIG. 15 which is an isometricview of the preferred embodiment of the invention. As can be seen in thefigure, the outlet conduit 22 is provided with a registering means suchas a tab 82 which fits in a tab receiver in the body 84 of the secondaryocclusion means. The outlet conduit has a circular orientation in thepreferred embodiment to reduce mechanical stress effects in an upwardfashion on the chamber.

In the preferred embodiment of the invention, the secondary occlusionmeans is an energizable solenoid 86 with a rod 88 moveable from anextended position to a withdrawn position in which in the withdrawnposition, the rod does not contact the chamber fluid outlet conduit 22.In the extended position, the rod contacts the conduit 22 to preventfluid flow through the conduit. In the preferred embodiment of theinvention, when the solenoid is not energized, the rod is in theextended position to occlude fluid flow. Thus, flow from the chamberwill always be occluded when the device is operating unless the controlmeans 32 energizes the solenoid 86 to retract the rod 88.

C First Occlusion Means

Referring now to FIG. 9, when the transfer set 34 is positioned in thedevice, the tray of set 38 is positioned so that the window 52 ispositioned adjacent to the first occlusion means 28. Each of theindividual fluid conduits 16 adjacent to the window 52 is positionedadjacent to multiple individual occluding arms 90 in the first occlusionmeans.

The operation of the first occlusion means is more clearly described inFIG. 8. As can be seen in the figure, the occlusion means includes aframe 92 for receiving a portion of each of the individual fluidconduits (not shown). As discussed above, each of the individual fluidconduits are positioned in a spaced-apart parallel relationship with oneanother in the frame. Multiple occluder arms 90 are pivotably mounted inthe frame. Each of the arms is pivotable from a first to a secondposition in which when each arm is in the first position, fluid flowthrough its respective individual fluid conduit 16 is totally occluded.When the arm 90 is in the second position, fluid flow through itsrespective conduit is allowed. The first occluder means 28 is providedwith a multiple individual biasing means for biasing each one of thearms in the first position. In the preferred embodiment of theinvention, the individual biasing means consists of a spring 94positioned at a first end 96 of each of the arms 90 to cause a secondend 98 of each of the arms to be forced toward the individual conduits16 to cause occlusion of the conduits. More specifically, each spring 94is positioned between the first end of the arm 96 and a portion of theframe 92 to cause occlusion of the individual conduits.

The first occluding means 28 is also provided with a first drive means100 for overcoming the individual biasing means 94 to force at least oneof the arms 90 into the second position in response to a command fromthe control means 32. In the preferred embodiment of the invention, thefirst drive means includes a drive screw 102 mounted in the frame in atraverse position with respect to the individual fluid conduits 16. Acarriage 104 is provided on the drive screw. In the preferred embodimentof the invention, a motor 105 is provided to rotate the drive screw inresponse to a command from the control means 32. The carriage ismoveable along the drive screw so that the carriage can be positionedimmediately below each of the individual occluder arms 90. A biasovercoming means 106 is mounted on the carriage 104 between the carriageand the individual occluder arms for overcoming only one of theindividual bias means, or springs, 90 when the bias overcoming means 106is immediately below one of the individual occluder arms 90. In thepreferred embodiment of the invention, the bias overcoming means 106 isa single solenoid 108 which includes a rod 110 moveable from a withdrawnposition to an extended position. In the withdrawn position, the roddoes not contact an adjacent occluder arm 90. In the extended position,the rod forces an adjacent occluder arm 90 from the first to the secondposition to cause the second end 98 of the occluder arm 90 to retractfrom its associated individual conduit 16. This allows fluid to flowthrough the individual conduit. In the preferred embodiment of theinvention, the rod 110 has a width that is less than the distancebetween the spaced apart portions of the individual occluding arms sothat only one of the occluding arms may be contacted at a time. Thisprovides a fail-safe means for insuring that fluid is allowed to flowthrough only one individual fluid conduit at a time.

In the preferred embodiment of the invention the frame 92 (FIG. 9) ofthe first occlusion means 28 includes an occluding surface 112 and ahinged door 114. The hinged door can be open to receive the windowportion 52 of the transverse set 34. The occluding surface 112 includesan aperture 116 to receive a portion of the second end 98 of each of theindividual occluding arms 90. The aperture is covered with a resilientmaterial 118 in the preferred embodiment of the invention to limit thepossibility of fluid leakage into the drive means 100 of the firstoccluder means 28. This resilient material 112 may be formed of siliconein the preferred embodiment.

In one embodiment of the invention, the frame 28 may include a sensingmeans for detecting the position of each of the individual fluidconduits 16 in the frame and for determining whether the individualfluid conduits are occluded by the arms. This sensing means may includea series of spring-loaded switches in the door 114 of the frame.Typically, these switches may be two-position switches which woulddetect the presence of an occlusion force on each of the individualfluid conduits when the door 114 is closed over the conduits. If aconduit is not in its appropriate position, or if an occlusion arm isnot properly biased to include its respective conduit, a relatively lowforce would be detected by the two-position sensors indicating apossible malfunction of the device.

In one embodiment of the invention, the tray of the transfer set and theframe of the first occluder are provided with a mating means to ensureproper placement of the tray in the frame of the first occluder. In thepreferred embodiment of the invention, as seen in FIG. 9, the matingmeans consists of a pair of outwardly extending pegs 120 in theoccluding surface 112 of the frame, and a corresponding pair ofapertures 122 in the tray of the transfer set. Thus, when an operatorplaces the tray of the transfer set into the frame of the occluder, theapertures 122 must be positioned over the pegs 112 in order for the door114 of the frame to close. This is one mechanism by which the positionof the individual fluid conduit lines 16 is checked for proper location.

F. Pressure Means

As discussed above, a pressure means 124 (FIG. 10) is provided forselectively creating positive and negative pressures in the chamber 18to control the rate of fluid flow through the chamber. The pressuremeans is in fluid communication with a second end 126 of the pressureconduit 26. In the preferred embodiment of the invention, the pressureconduit 26 is simply a conduit line 128 of the transfer set 34 asillustrated in FIG. 2. This conduit line 128, unlike the otherindividual conduit lines 16, is not connected to an individual sourcecontainer. Instead, the conduit line 128 is provided with a filter means130 for filtering air entering the conduit line 128 and is connected toa pump.

In the preferred embodiment of the invention, the filter means is a 0.22micron filter 130. A 0.22 micron filter is used in the preferredembodiment to provide a bacterial barrier between the chamber and theenvironment. The filter 130 includes a coupling device for coupling theair line 128 to a connector 132 in the pressure means as illustrated inFIG. 11. A flexible tubing 134 having a first end 136 open to theenvironment is positioned adjacent to a peristaltic pump 138. In oneembodiment of the invention, it may be desired to place a filter forfiltering out large particles in the air before the air enters the firstend 136 of the flexible tubing. The filter may be in the form of aporous plug 154 capable of filtering particles that are greater than0.22 microns.

The peristaltic pump can rotate in either direction to either pull airfrom the environment into the first end of the flexible tubing, or toforce air that is in the tubing out of the tubing. In the preferredembodiment of the invention as seen in FIG. 11, the tubing 134 canconsist of a first portion 140 and a second portion 142. The first andsecond portions can be connected to each other with a quick-disconnectcoupler 144. In the preferred embodiment of the invention, the firstportion of tubing is a highly compliant tube formed of silicone or othermaterial to increase the accuracy of the pump in terms controllingprecise amounts of air flow through the tubing with a minimum amount offorce from the peristaltic pump. The first and second portions of thetubing are connected to each other with a quick-disconnect device toallow the first portion to be replaced if it becomes worn from usage.

In one embodiment of the invention, the second portion of tubing 142 mayinclude a Y-site 146 or other junction. One leg of the junction 146 maybe connected to an air vent means 148 to provide a rapid return of airpressure in the line 142 to atmospheric pressure. This is very useful,for example, when it is desired to change the pressure in the chamber 18from a negative to a positive pressure to empty fluid in the chamberinto the receiving container 24. In the preferred embodiment of theinvention, the air vent means 148 consists of a conduit 150 having oneend open to the environment. A solenoid valve 152 is attached to the endopen to the environment to selectively open and close conduit 150 inresponse to signals from the control means as will be discussed morefully below. This feature is more clearly illustrated in FIG. 12.

In the preferred embodiment of the invention, the flexible tubing 134 isconnected to the pressure conduit 26 with a luer connection device.Other methods of connecting the flexible tubing 134 to the pressureconduit would be obvious to those skilled in the art based on theteachings herein.

In one embodiment of the invention, the device 10 may include first andsecond housings. A first housing 155 (FIG. 13) may house the controlmeans, while a second housing 157 (FIG. 14) may house the pumping meansof the first occluder and its associated tubing. The second housing maybe readily removed in the preferred embodiment of the invention toreplace the first portion 140 of tubing as required.

G. Load Cell

The device 10 also includes a sensing means 20 for sensing the amount offluid in the chamber 18 during operation of the device and forgenerating weight signals relating to the amount of fluid in thechamber. In the preferred embodiment of the invention, the sensing meansconsists of a load cell in contact with the chamber. The details of themechanical features of the load cell are more clearly illustrated inFIGS. 16 and 17. Referring now to FIG. 16, a load cell 156 is connectedto a chamber support 158. The chamber support 158 receives the chamber18. The load cell 156 senses the weight of the chamber and generatesweight signals which are indicative of the amount of fluid in thechamber. the electronics of the load cell are discussed in greaterdetail below in conjunction with a discussion of the control means.These signals pass through line 160 to the control means.

In the preferred embodiment of the invention, the load cell 156 isenclosed is a housing 162 as illustrated in FIG. 17. As can be seen inFIG. 17, the chamber support means 158 extends outside of the load cellhousing. A chamber housing 164 is also provided in the preferredembodiment of the invention to protect the chamber and the load cellfrom variations in load cell readings due to laminar air flow presentaround the device 10. The chamber housing 164 also prevents unnecessarytouch interference with the chamber. The chamber housing consists of alower portion 166 which is mounted on the load cell housing 162. Thelower portion 166 may be removed periodically to wash the housing.However, it is not necessary to remove the lower portion of the housingto insert a chamber 18 into the chamber support means 158. The upperportion 164 of the chamber housing in the preferred embodiment is ahinged lid which is attached to the first housing of the device 10.

H. Hanger System

In the preferred embodiment of the invention, each of the individualsource containers 12 is maintained in position by a unique hanger system168. The hanger system includes a pair of hooks 170 and 172 as can beseen in FIG. 19. These hooks are maintained in a parallel, spaced-apartrelationship with one another to provide a means for holding each sourcecontainer 12 in an inverted position. Each of the hooks generallyincludes a first vertically extending portion 174 (FIG. 18) and a secondgenerally perpendicularly extending portion 176 which extends from thelower end of the vertically extending portion. Each pair of hooks 170and 172 is maintained in a spaced-apart relationship with one anotherthrough the use of a spacer bar 178 and an adjustable spring means 180.The spring means 180 can be moved vertically along the first verticalportion 174 of the hooks to provide a downward pressure on eachindividual source container 12. Since various source containers may havegreatly different sizes, the spring means 180 provides a method ofadjusting to the various sizes of the source containers while providinga consistent pressure on each container to immobilize each sourcecontainer 12 during operation of the device. As can be seen in FIGS. 20and 21, each spring means includes a spring hook 182. Each spring hookincludes a first generally semicircular portion 184 which contacts thebase of a source container 12 when the source container is in theinverted position on hooks 170 and 172. The spring hook 182 alsoincludes a second generally rigid arm 186 which extends between thesemicircular portion 184 and a torsion device 188. The torsion device isenclosed in a housing 190 which is situated between the vertical portion174 of each pair of hooks 170 and 172 (FIG. 19).

Referring now to FIG. 21, the torsion means includes a torsion spring192. The torsion spring is mounted on a shaft 194. The shaft is thenconnected to a shaft end cap 196 and maintained in a flexed relationshipto the shaft end cap with a pin 198. The assembled spring, shaft andshaft end cap are then inserted through a cylindrical housing 200. Thehousing includes a keyway means 202 to receive one end 204 of the spring192. The assembly is maintained in the housing through the use of afirst and second retainer bushings 206 and 208. One retainer bushing 206also includes a keyway 210 for receiving a second end 212 of the spring192. Shaft 194 is integrally connected to a second shaft end cap 214.Both shaft and cap 214 and 196 include apertures 216 and 218 forreceiving a first vertical portion 174 of each of a pair of hooks 170and 172. Prior to placing the assembly illustrated in FIG. 1 over a pairof hooks, at least one of the retainer bushings 206 and 208 will berotated with respect to the other retainer bushing at least 180 degreesto create a tension on spring 192. The keyways 202 and 210 inconjunction with spring 192 create a constant downward pressure on thespring hook 182 after the assembly illustrated in FIG. 21 is mounted ona pair of hooks 170 and 172. A key feature of the device illustrated inFIGS. 18-21 is that the assembly illustrated in FIG. 21 is slidablyengaged with the vertical portions of each pair of hooks to adjust tosource containers of varying sizes. After the assembly illustrated inFIG. 21 has been mounted on a pair of hooks in the appropriate position,a locking knob 202 can be used to lock the assembly in a fixed positionover a source container.

OPERATION OF THE DEVICE

A. Overview

The operation of the device 10 is described in greater detail in thefollowing description. After a transfer set has been installed in thedevice, the operator is then ready to program the device to indicate theamount and type of each fluid to be transferred from each of theindividual source containers into the receiving container. Informationcan be input into the device from one of two sources. One source ofentering information into the device is a keyboard entry device,illustrated in FIG. 22. Another method of entering information into thedevice is through a computer terminal. The method of enteringinformation into the device using the keyboard display will be describedmore fully below. As will be apparent to one skilled in the art based onthe description given below, a very similar system would be used toinput information into the device using a personal computer.

B. Power Up-Master Microprocessor

When the device is turned on, a system of internal checks isautomatically performed by the control means 32. In the preferredembodiment of the invention, two microprocessors are used in the controlmeans 32. While a variety of microprocessors can be used, in oneembodiment of the invention, an Intel 8031 microprocessor can be usedfor both of the microprocessors. One microprocessor serves as a mastermicroprocessor and another microprocessor serves as a pumping controlmicroprocessor. A simplified block diagram of a typical microprocessoris illustrated in FIG. 23. As can be seen in this figure, a typicalmicroprocessor includes an internal random access memory 222 and aplurality of in/out (I/O) ports 224. The microprocessors include avariety of hardware registers which can be programmed to perform specialfunctions. In the preferred embodiments of the subject invention, thespecial function hardware registers 226 may include serial interfaceregisters 228, timer/counters 230, and stack pointer 232. Each of theaspects of the microprocessor as used in the preferred embodiment of thesubject invention will be discussed in greater detail below. Inaddition, to the internal features of a typical microprocessor asbriefly described above, additional external hardware is present in atypical microprocessor control device. For example, an external RAM 234,external in/out ports 236, and a programmable memory (ROM) 238 arerequired to allow a microprocessor to perform the desired functions inaccordance with the invention.

During power up of the device, various diagnostics and other checks areperformed simultaneously. These diagnostics are illustrated in the blockdiagram of FIG. 24. The diagnostics include: testing the internal RAM222 of each microprocessor as shown by block 240; testing an externalRAM 234 of each microprocessor as shown by block 242; initializinginternal and external RAMs 222,234 as shown by block 244; initializingall in/out ports 224 as shown by block 246; and initializing specialfunction hardware 226 located within the microprocessor (i.e. dedicatecertain ports 228 for communication purposes, initializing thetimer/counter 230 of each microprocessor, initializing the stack pointerfor keeping track of program routines).

C. Keyboard Programming Mode

In the preferred embodiment of the subject invention, afterinitialization procedures and diagnostics are performed, the controldevice 32 automatically defaults to a keyboard programming mode. Thekeyboard programming mode is the mode in which an operator can inputinformation into the device to cause the device to transfer specificamounts of fluid from specific individual source containers into thereceiving container. FIG. 22 illustrates a display panel for for thekeyboard entry device used in the preferred embodiment of the subjectinvention and FIG. 26 illustrates a display panel for displayingvolumetric and specific gravity information for each source container.The display panel displays the specific gravity as programmed by anoperator for a particular source container as illustrated by LCD displaypanel 250. The volume of fluid to be transferred from a specific sourcecontainer to the receiving container as programmed by an operator isillustrated by another LCD display panel 252. Each individual sourcecontainer has separate LCD display panels 250 and 252 for displaying thespecific gravity and volumetric information for each source container.

FIG. 27 is an illustration of a display panel for displaying the statusof the device during operation. Each of the displays illustrated in thisfigure will be discussed briefly here, and will be discussed in greaterdetail below with respect to actual operation of the device. Displaypanel 254 displays a patient I.D. number which is specific to eachindividual patient. This patient I.D. number can be entered into thedevice either through the keyboard entry device or a computer terminal.A unique identification number for each receiving container can bedisplayed in the bag I.D. display panel designated in 256 in FIG. 27.The "total delivered" display 258 can be used to display various typesof information. For instance, during a keyboard programming mode, the"total delivered" display displays in grams the weight as sensed by theload cell 20. While the device is actually pumping, the "totaldelivered" display will display the volume in milliliters of any fluidtransferred from the individual source containers. The circular "g"display 260 adjacent the "total delivered" display 258 will be litduring the keyboard entry mode to indicate that the informationdisplayed in the "total delivered" display is in grams. Similarly, the"ml" display 262 will be lit while the device is pumping to indicatethat the information displayed in the "total delivered" display is inmilliliters.

Other status displays include:

1. a "no flow" display 264 which indicates that no fluid is flowingduring operation of the device;

2. a "door" display 266 which indicates that a door is improperly closedduring operation of the device;

3. a "no set" display 268 indicates that a set is not present, or isimproperly positioned in the device during operation;

4. a "device" display 270 indicates a variety of device malfunctionsituations; and

5. a "power" display 272 indicates when the device is receiving power,and a "complete" display 274 indicates when a pumping operation has beencompleted.

The steps that an operator takes together with the internal functionsperformed by the control device in response to the operator's steps willnow be discussed in greater detail. The master microprocessor operatesduring the keyboard programming mode as follows. First, as illustratedby block 275 in FIG. 25, the microprocessor generates an updated displayevery one-half-second on the display panels illustrated in FIGS. 26 and27. Next, as illustrated by block 277 in FIG. 25, a display for anindividual source container such as displays 250 and 252 for sourcecontainer # 1 in FIG. 26 will be flashed to indicate to the operatorthat source container # 1 can now be programmed. The "Run" LED will alsobe lit. Only one set of displays will be flashed at a time and one "Run"LED will be lit so that it will be clear to the operator whichparticular source container is currently being programmed.

The programmer may then use the keyboard illustrated in FIG. 22 toprogram the amount of fluid to be transferred from that particularsource container to the receiving container. The programmer may eitherenter the volume or the specific gravity of the fluid to be transferred.Typically, during initial set up of the device, the specific gravity foreach source container will be initially programmed by the operator.

In order to input information concerning the specific gravity of aparticular source container into the device, the operator simplydepresses the specific gravity key 276 illustrated in FIG. 22. Thiscauses the keyboard programming mode to cause future information to beentered in a register programmed to retain specific gravity information.The programmer next may depress any one or more of the numeric keys 278as displayed in FIG. 22 and depress the "enter key" 280 to have theinformation entered in the register discussed above.

If a programmer does not wish to have fluid transferred from thatparticular source container, and volumetric information has beenpreviously entered in display panel 252, this information can be clearedsimply by depressing the "clear" key 282. The operator may then go tothe next source container display by depressing the enter key 280. Theoperator may continue pressing the "enter" key 280 until the display forthe desired source container display begins flashing. When the desiredsource container display has been reached, the operator may then inputinformation into the device for that particular source container in anidentical manner to the manner described above for source container # 1.

After the operator has completed entering information into the devicefor all the source containers, the operator may then press the start key284. If the start key is depressed, the keyboard programming mode beginsa pump control routine as illustrated by block 286 in FIG. 25. If the"start" key has not been depressed, the device remains in the keyboardprogramming mode unless the operator depresses either the "A ID" key288, or the "M ID" key 290. The "A ID" key will cause the device to exitthe keyboard programming mode, and enter an automatic identificationprogramming mode which is controlled from a remote computer terminal.The "M ID" key will also cause the device to exit the keyboardprogramming mode and enter a manual ientification programming mode,which is also controlled from a remote computer terminal.

D. Pump Control Routine

If the operator has depressed the start key, as discussed above, thedevice will enter a "pump control" routine. This routine is described inFIG. 28. As can be seen in the figure, the device first operates tocause the "ml" display 262 to light up, and turns off the light on the"g" display 260. This operation is illustrated by block 292 in FIG. 28.Next, the device continuously monitors the keyboard to determine if theoperator has depressed any key on the pad during the pumping mode. Thisis illustrated by block 294 in FIG. 28. This monitoring function isdescribed in greater detail in FIG. 29. If the operator has depressedthe stop key 296 (FIG. 22), the pump control routine will automaticallystop the pump control routine program as illustrated by block 298 (FIG.28).

Assuming the stop key has not been depressed, the next functionperformed by the pump control routine is to check the status of the pumpcontrol microprocessor to determine if it is waiting to receive data. Ifthe pump control microprocessor is ready to receive data, the mastermicroprocessor computes the weight of fluid to be transferred from eachindividual source container to the receiving container given the volumeand specific gravity information input in the device during the keyboardentry mode. This computation is essentially identical to thecomputations described in U.S. Pat. No. 4,513,796 entitled "High SpeedBulk Compounder" issued Apr. 30, 1985. This application is incorporatedherein by a reference. The pump control routine checks to see if any ofthe information entered by the operator is out of of a predeterminedrange. For instance, in the preferred embodiment of the invention, theallowable range for specific gravity is between approximately 0.5 and3.0. The minimum volume to be transferred has to be, for example, atleast one milliliter in the preferred embodiment of the invention. Ifany of the information is determined to be outside of these ranges, thepump control routine notifies the operator by causing the display 250 or252 (FIG. 26) which is out of range to flash. This is illustrated byblock 302 in FIG. 28.

After the out of range checks have been performed, if all informationinput into the device by the operator is within range, the pumping datacomputed by the program memory 238 and stored in its external RAM 234 istransferred through an external I/O ports 236 of the mastermicroprocessor to the external I/O ports 304 of the pumpingmicroprocessor. This information is then stored in the external RAM 300of the pumping microprocessor to be later used by the program memory 306of the pumping microprocessor. This transfer of information isillustrated by block 308 in FIG. 28.

After the information has been transferred to external RAM 300, the pumpcontrol routine then repeats the keyboard monitoring function discussedabove with respect to block 294. The master microprocessor remains inthis mode until it receives a signal from the pumping microprocessorindicating that the pump control microprocessor has started pumping.This is illustrated by decision diamond 310 in FIG. 28. If the pumpcontrol module has begun pumping, the master microprocessor begins amonitor pumping routine as illustrated by block 312 in FIG. 28.

E. Keyboard Logic Routine

Before discussing the monitor pumping routine in greater detail, thekeyboard logic routine illustrated by block 294 and 294(a) in FIG. 28will be discussed in greater detail. The keyboard logic routine isillustrated by the flow chart of FIG. 29. As can be seen in the flowchart, the first step performed in the routine is to decode any keywhich may have been pressed. This is illustrated by block 314 in thefigure. If a key has been pressed as illustrated by decision diamond316, the next step is to determine if it is a function key asillustrated by decision diamond 318. In the preferred embodiment of theinvention, the following keys have been designated as function keys: (1)clear; (2) decimal point; (3) enter; (4) enter/rinse; (5) recall; (6)start; and (7) stop. If any of the above keys have been depressed, theprogram logic operates to perform the appropriate function (such asclear the designated display). This step is indicated by block 320 inFIG. 29. The program logic then operates to exit the keyboard logicroutine and enter another appropriate routine, depending on whichfunction key has been depressed, and depending on how information wasoriginally entered into the device by the operator. For example, theprogram logic may exit to one of the following modes: (1) keyboardprogramming mode; (2) pump control routine; (3) auto identificationroutine; and (4) manual identification routine. The program logic willenter the auto and manual identification routines only if the start orstop keys have been depressed.

If a function key has not been depressed as determined by decisiondiamond 138, the next step is to determine if pumping is in process.This is illustrated by decision diamond 322 in FIG. 29. If pumping is inprogress, any other key entry made by an operator is ignored duringpumping, the keyboard logic routine is exited and the system logic willreturn to the location in the pump control routine from which it exited.This is illustrated by block 324 in FIG. 29.

If the device is not currently pumping fluid, then the keyboard logicroutine will next check to see if a mode key has been depressed. This isillustrated by decision diamond 326. The following keys have beendesignated as mode keys in the preferred embodiment of the invention:(1) auto zero; (2) auto span; (3) A ID; (4) M ID; (5) standard; and (6)verify. If any of the mode keys have been depressed, the appropriatefunction will be performed and the program logic will cause the deviceto exit from the keyboard logic routine to either the keyboardprogramming mode, auto I.D. mode, or manual I.D. mode. This isillustrated by block 328 in FIG. 29.

If a mode key has not been depressed, the next step is to determine if a"complete routine" is being executed. This check is illustrated bydecision diamond 330 in FIG. 29. The "complete routine" is simply aroutine performed by the master microprocessor after pumping has beencompleted by the pumping microprocessor. In this routine, the mastermicroprocessor waits for a signal from the pumping microprocessor toindicate that pumping has been completed. Once this signal is received,the master microprocessor causes the "complete" display 274 (FIG. 7.) tolight up, and causes the program logic to wait for additional commandsfrom the operator. if the complete routine is being exited asillustrated by decision diamond 330 in FIG. 29, the keyboard logicroutine will cause the master microprocessor to exit the keyboard logicroutine and enter the complete routine, as illustrated by block 332 inFIG. 29, thereby ignoring any keyboard entry made by the operatorrelating to volume, specific gravity, or numeric keys.

The next step performed by the keyboard logic routine, if the completeroutine is not being executed is to d determine if the operator hasdepressed a "parameter key". In the preferred embodiment of theinvention, the volume and specific gravity keys 280, and 276respectively are designated as "parameter keys". If either of these keyshas been depressed, the keyboard logic routine will cause the mastermicroprocessor to perform the appropriate function indicated by eitherof these keys as illustrated by block 334 in FIG. 29, and then cause themaster microprocessor to exit to the keyboard program routine asillustrated by block 346.

The next step performed by the keyboard logic routine is to determine ifa numerical key has been depressed. If so, the appropriate function isserviced as illustrated by block 348, and the microprocessor exits toeither the keyboard programming routine or the manual identificationroutine. This is illustrated by block 350.

F. Pump Monitoring Routine

The next routine to be described in greater detail is the pumpmonitoring routine illustrated in block 312 in FIG. 28. A more detaileddescription of this block is provided in FIG. 30. The pump monitoringroutine is a routine that is performed by the master microprocessorbased on information that it receives from the pumping microprocessor.As can be seen in FIG. 30, the first function performed during the pumpmonitoring routine is to refresh all displays on the device everyone-half second. This is illustrated by block 352. The pump monitoringroutine then monitors the keyboard as illustrated by block 354. Thisfunction is the same function performed during the pump control routineas illustrated by block 294 and 294(a) in FIG. 8, and illustrated as bythe flow chart of FIG. 29. The next step performed by the pumpmonitoring routine is to check to see if the stop key has been depressedby the operator. This check is illustrated by decision diamond 356 inFIG. 30. It should be noted that when any key is depressed, the pumpmonitoring routine will enter the keyboard logic routine from block 354.If the keyboard logic routine determines that the stop key has beendepressed, it will exit from the keyboard logic routine and return tothe pump monitoring routine. The check illustrated by decision diamond356 determines if the stop key has been depressed. If so, the pumpmonitoring routine will cause the microprocessor to exit the pumpmonitoring routine and go to a location designated as 358 in FIG. 28 ofthe pump control routine. This is illustrated by exit oval 360 in FIG.30.

Returning to decision diamond 356 in the pump monitoring routine, if thestop key has not been depressed, the enxt function performed by the pumpmonitoring routine is to determine if an alarm condition is present.This is indicated by block 362 of FIG. 30.

If an alarm condition is present, the program logic of the pumpmonitoring routine will cause the master microprocessor to exit the pumpmonitoring routine and enter an alarm routine as illustrated by exitoval 364.

If an alarm condition is not present, the next function performed by thepump monitoring routine is to update the weight delivered for thestation being pumped, and to update the total volume pumped in the totalvolume display. These functions are illustrated by block 366. After theupdate function has occurred, the next step is to determine if allstations have been pumped. This is illustrated by block 368 in FIG. 30.

If all stations have not been pumped, the program logic causes the pumpmonitoring routine to return to a location designated as location 370 inthe pump monitoring routine.

If all stations have been pumped, the pump monitoring routine will causethe master microprocessor to exit to location 358 in FIG. 28 of the pumpcontrol routine.

The next function performed in the pump control routine is to once againcheck to see if the stop key has been depressed. This is illustrated bydecision diamond 371 in FIG. 28.

G. Complete Routine

If the stop key has been depressed, the pump control routine will exitto the keyboard programming routine. If the stop key has not beendepressed, the pump control routine will then cause the mastermicroprocessor to begin the complete routine. This is illustrated byblock 372 in FIG. 28. The complete routine is also illustrated ingreater detail in FIG. 31. The first function performed by the completeroutine is to cause the complete LED 274 (FIG. 27) to light up. Thisfunction is illustrated by block 374 in FIG. 31. Next, all displays arerefreshed every one-half second. This is illustrated by block 376. Thekeyboard is then monitored as illustrated by block 378. The keyboardmonitoring function is the same routine discussed above, and illustratedin FIG. 29.

Next, the complete routine checks to see if the "A ID" "M ID" orstandard keys have been depressed by the operator. This is illustratedby decision diamond 380. If any of these keys have been depressed, thecomplete routine will cause the master microprocessor to enter anappropriate routine related to that particular key through a mastercontrol routine.

If an "A ID", "M ID", standard, or stop key has not been depressed, thenext function performed by the complete routine is to determine if the"start" key has been depressed by the operator. This is illustrated bydecision diamond 382. If the start key has not been depressed, thecomplete routine returns to the location designated as 384 in FIG. 31.If the start key has been depressed, the complete routine operates toturn off the "complete" LED 274 (FIGS. 27), and to turn on the "g" LED260. The master microprocessor then exits the complete routine.

H. Pumping Microprocessor

All of the control logic discussed above is performed by the mastermicroprocessor in the preferred embodiment of the invention. Thefunctions of pumping microprocessor will now be discussed in greaterdetail. The three major functions performed by the pumpingmicroprocessor are to: (1) control the pumping operation of theperistaltic pump; (2) process signals generated by the load cell; and(3) control the occlusion means. When the device is originally turned onby an operator, the pumping microprocessor goes through aninitialization process very similar to the initialization processdiscussed above with respect to FIG. 24.

I. Hold Routine

After the initialization process has been completed, the pumpingmicroprocessor automatically goes into a hold routine that isillustrated in detail by the flow chart of FIG. 32. As can be seen inthe figure, the first step performed by the hold routine is to clear anypumping data that may be present in a buffer in external RAM 300 of thepumping microprocessor. This step is illustrated by block 382 in FIG.32.

After this step has been completed, the next function performed by thehold routine is to send a signal to motor 105 of the first occlusionmeans 28 of FIG. 8. This signal causes the motor to advance solenoid 108to a "home position". In the preferred embodiment of the invention, the"home position" is a position in which the solenoid is immediatelyadjacent the occluding arm 90, which is closest to the motor 105.However, the "home position" may be located elsewhere on the drive screw102. The purpose of having a "home position" is to enable themicroprocessor to send future signals to the motor 105 to advance thesolenoid to other designated positions form a base, or "home position".The step of sending the solenoid to its "home position" is illustratedby block 384 in FIG. 32.

After the solenoid has been placed in its "home position", the nextfunction performed by the pumping microprocessor during the hold routineis to notify the master microprocessor that it may send new pumping datato the pumping microprocessor. This function is illustrated by block 386in FIG. 32. As will be recalled, during the pump control routinediscussed above with respect to FIG. 28, the master microprocessor willnot send pumping data to the pumping control microprocessor until themaster microprocessor receives a signal which indicates the pumpingmicroprocessor is ready to receive data. The pumping data is then sentby the master microprocessor to the pumping microprocessor asillustrated by block 308 in FIG. 28.

After the pumping microprocessor has notified the master microprocessorthat it may send new pumping data, the next function performed by thehold routine is to perform a check to see if the "stop key" has beenpressed by the operator. This check is illustrated by decision diamond388 in FIG. 32.

If the stop key has been pressed, the pumping microprocessor willautomatically exit from the hold routine and reset the pumpingmicroprocessor. In other words, the pumping microprocessor will returnto an initialization routine which is essentially identical to theinitialization routine performed by the master microprocessor when poweris initially applied to the microprocessor. This exit routine isillustrated by exit oval 390 in FIG. 32.

If the stop key has not been depressed, the next function performed bythe hold routine is to perform a check to see if the "Auto 0" key 392(FIG. 22) has been pressed. The purpose of the "Auto 0" key is to signalthe pumping microprocessor that the operator has requested the totalweight displayed in display panel 258 of FIG. 27 be set to zero. Thiscan be used, for example, to cause the display 258 to give a zeroreading when the chamber is empty, rather than give a reading whichindicates a weight of the chamber. Therefore, if the Auto 0 key 392 hasbeen depressed as indicated by decision diamond 394, the hold programperforms a tare load routine which subtracts the weight of the emptychamber from the displayed value in display panel 258 of FIG. 27. Thisfunction is illustrated by block 396 of FIG. 32.

The next function performed by the hold routine is to obtain a newweight reading from the load cell. This function is illustrated by block398 in FIG. 32. In order to more fully understand how this function isperformed, the electronics used to generate signals from the load cellwill now be discussed in greater detail. Refer now to FIG. 33 which is ablock diagram of the electronics associated with the load cell of thepreferred embodiment of the invention.

J. Load Cell

As can be seen in FIG. 33, a load cell 400 is powered by a regulated DCsource 402. As discussed above, the chamber is suspended from a bracketon the load cell so that the load cell 400 generates an analog signalwhich is indicative of the weight of both the chamber and any fluidcontained in the chamber. The load cell in the preferred embodiment ofthe invention, is a shear-beam type laod cell based on resistance straingauge technology. Weight values are converted by the load cell into DCsignal voltages. These voltages, or signals, are fed into a linearamplifier 404. The signal generated by the load cell 400 is a relativelylow level signal which requires amplification prior to transmission toan analog-to-digital converter. Linear amplifier 404 is a commerciallypackaged integrated circuit, low-noise, low-drift instrumentationamplifier. This instrumentation amplifier provides the bulk ofamplification needed to bring the low level signal from the load cell toa level adequate for input into the A/D converter. The signal fromamplifier 404 is then passed through a low-pass filter 406. This filterserves to attenuate noise components generate by semiconductors, seismiceffects and load cell mechanical resonance. The signal is then passedfrom the low-pass filter 406 to a "span trim and zero adjust" stage 408.The span trim function of this stage is used to set the overall loadcell amplifier gain (span) to a given millivolt/gram value required atthe input to an A/D converter 410. The zero adjust function assures aunipolar signal input voltage to the A/D converter, which is configuredin the unipolar mode. The signal is passed from the span trim and zeroadjust stage to an additional low-pass filter 412. The function oflow-pass filter 412 is essentially identical to the function of filter406. The signal then passes to the A/D convertor 410 through line 412.

K. A/D Convertor

The signal is then passed through line 413 to sample/hold 418 whichperiodically locks the incoming signal from low-pass filter 412 to astable value for conversion by A/D converter 410. The A/D conversionprocess is implemented by A/D converter 410 together with peripheralcircuitry consisting of clock oscillator 414, sample pulse timer 416 andpulse generator 336. The A/D converter 410 converts the amplitude valueof the signal from sample/hold 418 to an equivalent 14-bit binary codedoutput signal. This signal is transmitted through gates 420 and 422which sequentially place a high data byte and then a low data byte ondata bus lines 430 to the I/O port 304 of the pumping microprocessor.The information is then transmitted to a status buffer in internal ram450 of the pumping microprocessor. Gates 420 amd 422 transmit data tothe microprocessor after the microprocessor senses the end of conversionsignal via line 432 which is transmitted from a multiplexing gate 434.After the low data byte has been transferred, the A/D conversion cycleis completed, and begins again with the arrival of the next pulse into apulse generator 436.

L. Hold Routine - Continued

After an updated weight has been received from the load cell asillustrated by block 398 of FIG. 32, the next function performed by thepumping microprocessor is to update the internal RAM 222 of the mastermicroprocessor with weight information contained in internal ram 450 ofthe pumping microprocessor. This updating process takes place every fourtenths of a second in the preferred embodiment of the invention.Therefore, the information displayed in the display panel 258 is updatedcontinuously during the hold routine.

After the weight information has been sent to the master microprocessoras illustrated by block 452 of FIG. 32, the next function performed bythe pumping microprocessor during the hold routine is to perform a checkto see if the pumping microprocessor is still waiting for new pumpingdata. This check is illustrated by decision diamond 454. In thepreferred embodiment of the invention, the master microprocessor onlysends data to the pumping microprocessor when the operator has pressedthe start button 284 (FIG. 22). When the start button is pressed, thismeans that the operator has completed entering pumping information for aspecific patient. Once this information has been entered and the startbutton has been depressed, the master processor continues to send thisinformation to the pumping microprocessor until the pumpingmicroprocessor confirms that valid data has been sent to the pumpingmicroprocessor. Once the pumping microprocessor has confirmed that validdata has been received from the master microprocessor, the pumpingmicroprocessor exits from the hold routine of FIG. 32, and returns to amaster control routine which will be discussed in greater detail below.

M. Pumping Routine

The control routine will next cause the pumping microprocessor to enterinto a pumping routine which is discussed in greater detail in FIG. 34.As can be seen in the figure by block 456, the first function performedby the pumping routine is to obtain a "tare weight" of the chamber 18while it is empty. A tare weight is simply the weight of the emptychamber. After this information has been obtained, the tare weight isstored in a buffer in internal RAM 450 of the pumping microprocessor.

The next function performed by the pumping routine is to obtain a weightto pump from the first (or next) available source container. Thisfunction is illustrated by block 458 of FIG. 34. As discussed above, theweight information is stored in an external RAM 300 of the pumpingmicroprocessor until it is transferred during the pumping routine to abuffer in the internal RAM 450 of the microprocessor.

After this information has been transferred, the next function performedby the pumping routine is to perform a check to see if any fluid is tobe pumped from a source container. This check is illustrated by decisiondiamond 460 of FIG. 34.

If further pumping is required, the next step performed by the functionroutine is to perform a check to see if less than 50 milliliters needsto be pumped. This check is illustrated by decision diamond 462 of FIG.34. If more than 50 milliliters is to be pumped from a source container,the intermediate chamber is filled an integral number of times asrequired to pump the closest integral multiple of 50 milliliters of thetotal volume of fluid to be pumped from a single source container. Thereason this step is performed in the preferred embodiment of theinvention is because the maximum capacity of the chamber is 50 ml. Thisfunction is illustrated by block 464 in FIG. 34.

If less than 50 ml. is to be pumped, or after the closest integralmultiple has been pumped during the step discussed above, the nextfunction performed by the pumping routine is to fill the chamber withany weight remaining to be pumped from that particular source container.This function is illustrated by block 468 in FIG. 34. In the preferredembodiment of the invention, the smallest weight of fluid to be pumpedmay be as low as 1 ml. However, in other embodiments of the invention,it may be possible to pump volumes as low as 0.5 ml. The fill functionsillustrated by blocks 464 and 468 of FIG. 34 are discussed in muchgreater detail below with respect to FIG. 5.

The next function performed by the pumping routine is to drain theintermediate chamber if appropriate. This function is illustrated byblock 470 and will be discussed in greater detail with respect to FIG.36.

The next function performed by the pumping routine is to perform a rinseoperation. This function is illustrated by block 472 of FIG. 34 anddiscussed in greater detail below with respect to FIG. 37.

After the chamber has been rinsed (if necessary), the next functionperformed by the pumping routine is to update the pumping status for themaster microprocessor based on information from the load cell obtainedduring the pumping or rinsing operation. This function is illustrated byblock 474 of FIG. 34.

The pumping routine then performs a check to see if fluid from allnecessary source containers has been pumped. This check is illustratedby decision diamond 476 of FIG. 34. If fluid from all necessary sourcecontainers for a particular patient have not yet been pumped, thepumping routine returns to the location designated as 478 in FIG. 34 toobtain the weight to pump for the next required source container. If allnecessary fluid has been pumped, the pumping routine then exits to amaster control routine as illustrated by exit oval 480 in FIG. 34.

N. Fill Routine

The precise mechanism and procedures by which fluid is actually pumpedfrom the source containers into the chamber by the control means asillustrated by blocks 464 and 468 of the pumping routine will now bediscussed in greater detail with respect to FIG. 35. As can be seen inthe figure, the first function performed during the "fill routine" ofFIG. 35 is to perform a check to see if the chamber is to be filled amultiple number of times from a single source container adjacent thebias overcoming means 106 of the first occlusion means 28. This check isillustrated by decision diamond 481 in FIG. 35. If the bias overcomingmeans is not adjacent the appropriate occlusion arm 94, for theappropriate source container, the pumping microprocessor sends a signalto motor 105 to advance carriage 104 to position the bias overcomingmeans 106 adjacent the appropriate occluding arm 90 of the appropriatesource container 12. This function is illustrated by block 482.

The next function performed by the fill routine is to obtain a tareweight from the load cell for the chamber. This function is illustratedby block 484 in FIG. 35.

The next function performed by the fill chamber routine is to allow thechamber to stabilize to atmospheric pressure. This function isillustrated by block 485. The chamber can be quickly brought toatmospheric pressure in the preferred embodiment of the subjectinvention by allowing solenoid valve 152 in FIG. 12 to open to admit thepressure conduit, line 128, to suddenly go to atmospheric pressure. Thisin turn causes the pressure in the chamber to reach atmosphericpressure.

In the preferred embodiment of the invention, the next functionperformed by the fill chamnber routine is to check to see if the weightto be pumped is less than 6.0 grams. This check is illustrated bydecision diamond 486. If the weight to be pumped is less than 6.0 grams,the control means sends a signal to the peristaltic pump to cause thepump to rotate in a first direction to create a vacuum in the chamber.In the preferred embodiment of the invention, if the weight to be pumpedis less than 6.0 grams, the control means causes the peristaltic pump tooperate at one-third at its rated speed. This function is illustrated byblock 488 in FIG. 35.

If the weight to be transferred is not less than 6.0 grams, the nextfunction performed by the fill chamber routine, is to perform a check tosee if the weight should be pumped is less than 11.0 grams. This checkis illustrated by decision diamond 490 in FIG. 35. if the weight to bepumped is between 6.0 grams and 11.0 grams, the control means sends asignal to the peristaltic pump to cause the pump to rotate in the firstdirection to create a vacuum in the chamber. However, in this instance,the signal causes the pump to operate at two-thirds of its rated speed.This function is illustrated by block 492 of FIG. 35.

The next function performed by the fill chamber routine is to send asignal to the peristaltic pump to rotate in the first direction at fullspeed if the weight to be transferred is greater than or equal to 11.0grams. This function is illustrated by block 494 in FIG. 35.

It should be noted that up to this point in the fill chamber routine, nofluid is actually being pumped into the chamber because the firstocclusion means is biased so that all of the individual conduit linesare occluded. The next function performed by the fill chamber routine isto send a signal to solenoid 108 of the first occlusion means to causerod 110 of the solenoid 108 to move into an extended position, therebycausing occluding arm 90 to move away from its associated individualfluid conduit 16 to allow fluid to flow from the appropriate sourcecontainer into the chamber. The step of opening the appropriate supplyvalve is illustrated by block 496 in FIG. 35.

The next function performed by the fill routine is to allow the chamberto fill to the desired weight as the peristaltic pump creates a vacuumin the chamber to draw fluid from a single source container into thechamber. As fluid is being drawn into the chamber, the load cell isconstantly generating an analog signal which is sent to the A/Dconvertor to create a digital signal which is then transmitted to thepumping microprocessor. This function is illustrated by block 498.

When the signal from the load cell indicates that the desired amount offluid has been transferred to the chamber, the next function performedby the fill chamber routine is to turn off the peristaltic pump andde-energize solenoid 108 to prevent further fluid flow. This function isillustrated by block 500.

The next function performed by the fill routine is to once again allowthe chamber to stabilize to atmospheric pressure. This function isillustrated by block 502, and is essentially identical to the functiondiscussed above with respect to block 485. The pumping microprocessorthen exits the fill routine and returns to the pumping routine at thelocation designated as element 504 in FIG. 34.

O. Drain Routine

The drain routine discussed above with respect to block 470 of FIG. 34will now be discussed in greater detail below referring to FIG. 36. Therain routine is simply a series of checks to determine if the chamberneeds to be drained. The first check performed by the drain routine isto determine if the last source container has been pumped. This check isillustrated by decision diamond 506 in FIG. 36. If the last sourcecontainer has not been pumped, the drain routine next checks to see if arinse is to follow the source container that was just pumped. This checkis illustrated by decision diamond 508. Normally, a rinse will not beconducted unless the next fluid to be pumped is incompatible with theprevious fluid, or if the previous fluid pumped was the last fluid to bepumped. The next check performed by the drain chamber routine is todetermine if the next source container to be pumped is supposed to befollowed by a rinse. This is illustrated by decision diamond 510. In thepreferred embodiment of the invention, if the next source container isto be followed by a rinse, then a drain operation will occur prior tofilling the chamber with that fluid.

The next check performed by the drain chamber routine is to determine ifmultiple fills of 50 mls are occurring in the intermediate chamber. Thisis illustrated by decision diamond 512. The next check performed by thedrain chamber routine is to determine if all of the remaining sourcecontainers contain fluid which is not required to be pumped into thechamber for a particular patient. This check is illustrated by decisiondiamond 514.

The final check performed by the drain chamber routine is to determineif the current volume in the intermediate chamber and the volume to bepumped from the next source container is less than 50 mls. This isillustrated by decision diamond 516. If the volume in the chamber andthe volume to be pumped from the next source container is less than 50mls, the pumping microprocessor will return to the pumping routine atthe location designated by element 518 in FIG. 34. This will allow thepumping routine to cause the next fluid to be pumped into the chamberprior to draining the chamber. For all of the checks performed by thedrain chamber routine discussed above, if the outcome to any one of thechecks is in the affirmative, the pumping microprocessor will cause thesecond occluding means to open the fluid outlet conduit 22 to allow thefluid in the chamber to drain into the receiving container.

The device is unique in that during the drain operation, the peristalticpump operates in the reverse direction to generate a positive pressurein the chamber to force the fluid out of the chamber. After anynecessary drain operation has occurred as indicated by the drain chamberroutine, the pumping microprocessor exists the drain routine and returnsto the pumping routine at the location designated by element 518 in FIG.34.

P. Rinse Operation

As discussed above, the next function performed by the pumping routineis to perform a rinse operation as illustrated by block 472 in FIG. 34.This operation will now be discussed in much greater detail below withrespect to FIG. 37. As can be seen in FIG. 37, the first functionperformed during the rinsing operation is to perform a check todetermine if the chamber needs to be rinsed after fluid has beentransmitted from a particular source container. An operator of thedevice may indicate that a rinse is required when information is beingentered into the device. For example, if information is to be enteredthrough a keyboard, as discussed above, then the operator may simplydepress the "ENT RIN" key 520 (FIG. 22) with respect to a particularsource container. If the information is being entered into the devicethrough a computer terminal, then other means would be used to indicatethat a particular source container requires a rinse after fluid has beentransmitted from that source container. In any event, if a rinse isrequired, then a rinse display 222 (FIG. 26) will indicate that a rinseis required after fluid from that particular source container istransmitted to the chamber.

If a rinse is required, the next function performed by the pumpingmicroprocessor during the rinse routine as illustrated by FIG. 37 is toallow the chamber to stabilize to atmospheric pressure. This function isillustrated by block 524. The chamber is allowed to stabilize atatmospheric pressure using the technique discussed above with respect toblock 485 in FIG. 35. The pumping microprocessor then sends a signal tothe peristaltic pump 105 to cause the peristaltic pump to rotate in afirst direction at full speed to create a vacuum in the chamber. Thisfunction is illustrated by block 526. The pumping microprocessor nextsends a signal to the second occlusion means to energize its associatedsolenoid valve thereby creating an open fluid communication between thechamber and the receiving container. This function is illustrated byblock 528. The vacuum in the chamber causes fluid in the receivingcontainer to be drawn into the chamber to rinse the chamber.

In the preferred embodiment of the invention, the rinsing routine allowsthe chamber to completely fill from the receiving container as theweight of the chamber is continuously monitored by the load cell. Thisfunction is illustrated by block 530. After the load cell has indicatedthat the chamber has filled, the next function performed by the pumpingmicroprocessor during the rinse routine is to allow the chamber tostabilize once again to atmospheric pressure. This function isillustrated by block 532.

The next function performed by the rinse routine is to generate apositive pressure in the chamber using the techniques described above tocause the rinse fluid in the chamber to return to the receivingcontainer. This is illustrated by block 534. After the chamber has beendrained, the pumping microprocessor returns to the pumping routine atthe location designated by element 536 in FIG. 34.

Q. Control Routine - Pumping Microprocessor

All of the routines discussed above are controlled by a pair of mastercontrol routines. Each microprocessor has its own master control routineto direct each microprocessor to the appropriate routine duringoperation of the device. The master control routine for the pumpingmicroprocessor will now be discussed in greater detail below withrespect to FIG. 38. As can seen in the figure, the first functionperformed by the control routine is to initialize the pumpingmicroprocessor. This function is illustrated by block 340.

The next funtion performed by the control routine for the pumpingmicroprocessor is to determine if any alarms have been generated. Thisis illustrated by decision diamond 346. The next function performed ifno alarms have been generated, is to enter the pumping routine discussedabove with respect to FIG. 34. This function is illustrated by block 348in FIG. 38. The control routine then checks again to see if an alarm hasbeen generated as illustrated by decision diamond 350. If no alarms havebeen generated, the control routine will then cause the pumpingmicroprocessor to enter a complete routine. The complete routine issimply a routine which is performed after pumping has been completed.The complete routine causes the solenoid of the first occluder to besent to its "home position". The complete routine also causes thepumping microprocessor to continue to read and filter information fromthe load cell.

The control routine for the pumping microprocessor then checks onceagain to see if any alarms have been generated as illustrated bydecision diamond 354. If no alarms have been sounded, the entire controlroutine is repeated.

If at any point during the control routine described above an alarm isgenerated, the control routine will enter into an alarm routine. Afterappropriate action has been taken in response to the alarm, the controlroutine for the pumping microprocessor will be initiated once again.

R. Control Routine-Master Microprocessor

The control routine for the master microprocessor will now be discussedin greater detail below with respect to FIG. 39. As can be seen in thefigure, the first function performed by the master control routine is toinitialize the system. This is illustrated by block 360. Theinitialization procedure has been discussed above. After the mastermicroprocessor has been initialized the master control routine nextperforms a check to determine if it is necessary to enter the keyboardprogramming mode discussed above with respect to FIG. 25. This check isillustrated by decision diamond 362 in FIG. 39. If it is not appropriateto enter the keyboard programming mode, the next check performed by themaster control routine is to determine if it is appropriate to enter theauto identification mode. This check is illustrated by decision diamond364.

The next check performed by the master routine is to determine if it isappropriate to enter the manual identification mode. This check isillustrated by decision diamond 366. If it has been determined duringeach of the three checks described above to enter into one of thevarious modes in which information is entered by an operator into thedevice, the master control routine will allow the information to beentered. However, as can be seen in FIG. 39, during this process, themaster control routine is continuously checking for the presence of anyalarms generated by the system. In the event that any alarm has beengenerated, the master control routine will cause the mastermicroprocessor to enter into an alarm processing routine. If the alarmis one from which the device can be recovered from easily, theappropriate action will be taken, and the master control routine willreturn to a default mode of keyboard programming in the preferredembodiment of the invention. If the alarm is not a "recoverable alarm",then the master control routine will cause the master microprocessor toreturn to the location designated by element 370 in FIG. 39.

In one embodiment of the invention, a means may be provided forgenerating a record of the actual transfer of multiple fluids into asingle source container. In this embodiment, information generated bythe master and pumping microprocessors may be transmitted to a standardprinter through appropriate software to generate a written record of theactual fluid and amount of fluid transferred.

Although the invention has been described and illustrated in detail, itis to be clearly understood that the same is by way of illustration andexample only, and is not to be taken by way of limitation; the spiritand scope of this invention being limited only by the terms of theappended claims.

We claim:
 1. A device for accurately transferring multiple individualfluids from multiple source containers to a single receiving container,in which fluid flows from said multiple source containers throughindividual fluid conduits to a chamber having a chamber fluid outletconduit in fluid communication with the single receiving container, thechamber also having a pressure conduit, the invention comprising:firstocclusion means for selectively preventing fluid flow from each of saidindividual fluid conduits to said chamber; pressure means forselectively creating positive and negative pressures in said chamber tocontrol the rate of fluid flow through said chamber; second occlusionmeans for selectively occluding fluid flow from said chamber outletfluid conduit to said receiving container; and control means forcontrolling said first and second occlusion means and said pressuremeans, said control means causing said first occlusion means to allowfluid to flow through at least one of said individual fluid conduitswhile causing said second occlusion means to prevent fluid flow intosaid receiving container and simultaneously p1 causing said pressuremeans to create a negative pressure in said chamber to precisely controlthe amount of fluid flow into said chamber, said control means furthercausing said first occlusion means to prevent fluid flow through all ofsaid individual fluid conduits after a predetermined amount of fluid hasbeen delivered to said chamber, said control means then further causingsaid second occlusion means to allow fluid to flow from said chamberthrough said outlet conduit while simultaneously causing said pressuremeans to create a positive pressure in said chamber to force fluid fromsaid chamber into said receiving container.
 2. A device for accuratelytransferring multiple individual fluids as recited in claim 1, whereinsaid first occlusion means further includes:multiple individual occludermeans for providing each individual fluid conduit a respectiveindividual occluder means.
 3. A device for accurately transferringmultiple individual fluids as recited in claim 2, wherein said multipleindividual occluder means further includes:a frame for receiving aportion of each of said individual fluid conduits, each of saidindividual fluid conduits being in a spaced-apart parallel relationshipwith one another in said portion in said frame; multiple occluder armspivotably mounted in said frame, each of said arms being pivotable froma first to a second position wherein when said arm is in said firstposition, fluid flow through one of said conduits is totally occluded,and when said arm is in said second position, fluid flow through saidone of said conduits is allowed, each conduit having an associatedoccluder arm.
 4. A device for accurately transferring multipleindividual fluids as recited in claim 3, wherein said multipleindividual occluder means further includes:first occluder meansincluding a multiple individual biasing means for biasing each of saidarms in said first positions; and first drive means for overcoming saidindividual biasing means to force at least one of said arms into saidsecond position in response to a first command from the control means.5. A device for accurately transferring multiple individual fluids asrecited in claim 4, wherein said first drive means furtherincludes:means for insuring that fluid is allowed to flow through anindividual fluid conduit at a time.
 6. A device as recited in claim 5wherein said fail-safe means further includes:a drive screw mounted insaid frame in a traverse position with respect to said individualconduits; a carriage on said drive screw, said carriage being moveableon said drive screw so that said carriage can be positioned adjacenteach of said individual occluder arms; and bias overcoming means mountedon said carriage between said carriage and said individual occluder armsfor overcoming only one of said individual bias means when said biasovercoming means is adjacent one of said individual occluder arms.
 7. Adevice as recited in claim 6 wherein said bias overcoming means furtherincludes:a solenoid including a rod movable from a withdrawn position toan extended position, in said withdrawn position said rod does notcontact an adjacent occluder arm and in said extended position said rodforces said adjacent occluder arm from said first to said secondposition, said rod having a width that is less than the distance betweensaid spaced apart portions of said individual occluding arms so thatsaid rod is capable of contacting only one of said individual occludingarms at a time.
 8. A device for accurately transferring multipleindividual fluids from multiple source containers to a single receivingcontainer, in which fluid flows from said multiple source containersthrough individual fluid conduits to a chamber having a chamber fluidoutlet conduit in fluid communication with the single receivingcontainer, the chamber also having a pressure conduit, the pressureconduit having a first end in fluid communication with said chamber anda second end, said pressure conduit also having an air filter betweensaid first and second ends, said air filter creating a sterile barrierbetween the interior of said pressure conduit and the environment theinvention comprising:first occlusion means for selectively preventingfluid flow from each of said individual fluid conduits to said chamber;pressure means for selectively creating positive and negative pressuresin said chamber to control the rate of fluid flow through said chamber,said pressure mean being in fluid communication with said second end ofsaid pressure conduit; second occlusion means for selectively occludingfluid flow from said chamber outlet fluid conduit to said receivingcontainer; and control means for controlling said first and secondocclusion means and said pressure means, said control means causing saidocclusion means to allow fluid to flow through at least one of saidindividual fluid conduits while causing said second occlusion means toprevent fluid flow into said receiving container and simultaneouslycausing said pressure means to create a negative pressure in saidchamber to precisely control the amount of fluid flow into said chamber,said control means further causing said first occlusion means to preventfluid flow through all of said individual fluid conduits after apredetermined amount of fluid has been delivered to said chamber, saidcontrol means then further causing said second occlusion means to allowfluid to flow from said chamber through said outlet conduit whilesimultaneously causing said pressure means to create a positive pressurein said chamber to force fluid from said chamber into said receivingcontainer.
 9. A device as recited in claim 8 wherein said pressure meansfurther includes:air forcing means for forcing air into and out of saidpressure conduit to create said positive and negative pressures in saidchamber.
 10. A device as recited in claim 9 wherein said air forcingmeans further includes:a pump; and flexible tubing having first andsecond open ends, said first end of said tubing being in fluidcommunication with said second end of said pressure conduit, said pumpcontacting said tubing between said first and second ends of tubing toalternately force air from the environment into the tubing and, thus,into said pressure conduit to create a positive pressure in said chamberand withdraw air from the tubing, and thus, into said pressure conduitto create a negative pressure in said chamber.
 11. A device as recitedin claim 10 wherein said pump is a perstalic pump.
 12. A device asrecited in claim 10 wherein said flexible tubing further comprises;firstand second portions, said first portion including said first end of saidtubing, said first portion contacting said pump, said second portionincluding said second end of said tubing, said second portion beingformed of a highly compliant material and said first portion beingformed of a less compliant material, said first and second portionsbeing in fluid communication with each other, said first and secondportions being capable of being disconnected from each other.
 13. Adevice as recited in claim 12 further comprising:a first housing forhousing said first portion of said flexible tubing; and a second housingfor housing said second portion of said flexible tubing, said secondhousing being removable to allow periodic replacement of said secondportion of said tubing.
 14. A device as recited in claim 13 furthercomprising:a quick disconnect device for connecting said first andsecond portions to one another.
 15. A device as recited in claim 10further comprising:luer connecting means for connecting said first endof said tubing to said second of said pressure conduit.
 16. A device asrecited in claim 10 further comprising:filter means for filtering airentering said second end of said flexible tubing.
 17. A device asrecited in claim 16 wherein said filter means filters particles greaterthan 0.5 microns.
 18. A device as recited in claim 16 wherein saidfilter means further includes:a porous plug inserted in said second endof said flexible tube.
 19. A device for accurately transferring multipleindividual fluids from multiple source containers to a single receivingcontainer, in which fluid flows from said multiple source containersthrough individual fluid conduits to a chamber having a chamber fluidoutlet conduit in fluid communication with the single receivingcontainer, the chamber also having a pressure conduit, the inventioncomprising:first occlusion means for selectively preventing fluid flowfrom each of said individual fluid conduits to said chamber; pressuremeans for selectively creating positive and negative pressures in saidchamber to control the rate of fluid flow through said chamber; secondocclusion means for selectively occluding fluid flow from said chamberoutlet fluid conduit to said receiving container said second occlusionmeans being normally biased in a closed position to occlude said chamberoutlet fluid conduit; and control means for controlling said first andsecond occlusion means and said pressure means, said control meanscausing said occlusion means to allow fluid to flow through at least oneof said individual fluid conduits while causing said second occlusionmeans to prevent fluid flow into said receiving container andsimultaneously causing said pressure means to create a negative pressurein said chamber to precisely control the amount of fluid flow into saidchamber, said control means further causing said first occlusion meansto prevent fluid flow through all of said individual fluid conduitsafter a predetermined amount of fluid has been delivered to saidchamber, said control means then further causing said second occlusionmeans to allow fluid to flow from said chamber through said outletconduit while simultaneously causing said pressure means to create apositive pressure in said chamber to force fluid from said chamber intosaid receiving container.
 20. A device as recited in claim 19 whereinsaid second occlusion means further includes:an energizable solenoidincluding a rod movable from an extended position to a withdrawnposition, in said withdrawn position said rod does not contact saidchamber fluid outlet conduit and in said extended position said rodoccludes said chamber fluid outlet conduit, when said said solenoid isnot energized, said rod is in said extended position.
 21. A device foraccurately transferring multiple individual fluids from multiple sourcecontainers to a single receiving container, in which fluid flows fromsaid multiple source containers through individual fluid conduits to achamber having a chamber fluid outlet conduit in fluid communicationwith the single receiving container, the chamber also having a pressureconduit, the invention comprising:first occlusion means for selectivelypreventing fluid flow from each of said individual fluid conduits tosaid chamber; pressure means for selectively creating positive andnegative pressures in said chamber to control the rate of fluid flowthrough said chamber; second occlusion means for selectively occludingfluid flow from said chamber outlet fluid conduit to said receivingcontainer; sensing means for sensing the amount of fluid in said chamberduring operation of said device and for generating weight signalsrelated to the amount of fluid in said chamber; and control means forcontrolling said first and second occlusion means and said pressuremeans, said control means causing said first occlusion means to allowfluid to flow through at least one of said individual fluid conduitswhile causing said second occlusion means to prevent fluid flow intosaid receiving container and simultaneously causing said pressure meansto create a negative pressure in said chamber to precisely control theamount of fluid flow into said chamber, said control means furthercausing said first occlusion means to prevent fluid flow through all ofsaid individual fluid conduits after a predetermined amount of fluid hasbeen delivered to said chamber, said control means then further causingsaid second occlusion means to allow fluid to flow from said chamberthrough said outlet conduit while simultaneously causing said pressuremeans to create a positive pressure in said chamber to force fluid fromsaid chamber into said receiving container.
 22. A device for accuratelytransferring multiple individual fluids from multiple source containersto a single receiving container, as recited in claim 21 wherein:saidsensing means includes a load cell in contact with said chamber.
 23. Adevice for accurately transferring multiple individual fluids frommultiple source containers to a single receiving container as recited inclaim 22 wherein:said sensing means includes a chamber support means forreceiving and support said chamber, said chamber support means beingattached to said load cell so that additional weight on said chambersupport means will be conducted to said load cell for sensing.
 24. Adevice for accurately transferring multiple individual fluids frommultiple source containers to a single receiving container as recited inclaim 23 wherein:said sensing means includes a housing, said housingsurrounding said chamber support means and said chamber when said deviceis in operation for reducing the possibility of said load cell frominaccurately sensing the weight on said chamber support means duringoperation of the device.
 25. A device for accurately transferringmultiple individual fluids from multiple source containers to a singlereceiving container, as recited in claim 22 wherein said control meanscomprises:source container indicating means for receiving sourcecontainer indicating signals from an operator of said device, saidsource container indicating signals indicating the particular ones ofsaid individual fluids to be transferred from said particular ones ofsaid source containers to said receiving container; and amountindicating means for receiving amount indicating signals from anoperator of said device, said amount indicating signals indicating theamount of each of said particular ones of said individual fluids to betransferred from said particular ones of said source containers to saidreceiving container.
 26. A method for transferring multiple individualfluids from multiple source containers to a single receiving container,in which fluid flows from said multiple source containers throughindividual fluid conduits to a chamber having a single chamber fluidoutlet conduit in fluid communication with the single receivingcontainer, the chamber also having a pressure conduit, the inventioncomprising the steps of:(a) receiving source container indicatingsignals from an operator of said device, said source containerindicating signals indicating the particular ones of said individualfluids to be transferred from said particular ones of said sourcecontainers to said receiving container and receiving amount indicatingsignals from an operator of said device, said amount indicating signalsindicating the amount of each of said particular ones of said individualfluids to be transferred from said particular ones of said sourcecontainers to said receiving container; (b) allowing fluid to flow fromat least one of said source containers as indicated by said sourcecontainer indicating signals into said chamber while preventing fluid toflow from said chamber to said receiving container; (c) sensing theamount of fluid transferred from said least one of said sourcecontainers into said chamber; (d) preventing fluid from flowing fromsaid at least one of said source containers into said chamber after theamount of fluid indicated by said amount indicating signals has enteredsaid chamber; and (e) allowing fluid to flow from said chamber to saidreceiving container.
 27. A method for transferring multiple individualfluids from multiple source containers to a single receiving container,as recited in claim 26 further comprising:creating a negative pressurein said chamber while allowing fluid to flow from at least one of saidsource containers as recited in step (b), said negative pressure forprecisely controlling the amount of fluid transferred from said sourcecontainers to said chamber.
 28. A method for transferring multipleindividual fluids from multiple source containers to a single receivingcontainer, as recited in claim 26 further comprising:creating a positivepressure in said chamber while allowing fluid to flow from said chamberas recited in step (e), said positive pressure for enhancing flow offluid from said chamber to said receiving container.
 29. A method fortransferring multiple individual fluids from multiple source containersto a single receiving container, as recited in claim 27 furthercomprising:creating a positive pressure in said chamber while allowingfluid to flow from said chamber as recited in step (e), said positivepressure for enhancing flow of fluid from said chamber to said receivingcontainer.
 30. A method for transferring multiple individual fluids frommultiple source containers to a single receiving container, as recitedin claim 26 further comprising the additional steps of:(f) transferringfluid in said receiving container into said chamber; and (g) returningfluid from said chamber back to said receiving container.
 31. A methodfor transferring multiple individual fluids from multiple sourcecontainers to a single receiving container, as recited in claim 30further comprising during step (f):preventing fluid to flow from saidsource containers and creating a negative pressure in said chamber. 32.A method for transferring multiple individual fluids from multiplesource containers to a single receiving container, as recited in claim30 further comprising during step (g):preventing fluid to flow from saidsource containers and creating a positive pressure in said chamber. 33.A device for accurately transferring multiple individual fluids frommultiple source containers to a single receiving container, in whichfluid flows from said multiple source containers through individualfluid conduits to a chamber having a chamber fluid outlet conduit influid communication with the single receiving container, the chamberalso having a pressure conduit, the invention comprising:first occlusionmeans for selectively preventing fluid flow from each of said individualfluid conduits to said chamber; pressure means for selectively creatingpositive and negative pressures in said chamber to control the rate offluid flow through said chamber; second occlusion means for selectivelyoccluding fluid flow from said chamber outlet fluid conduit to saidreceiving container; sensing means for sensing the amount of fluid insaid chamber during operation of said device and for generating signalsrelated to the amount of fluid in said chamber; and control means forcontrolling said first and second occlusion means and said pressuremeans, said control means causing said first occlusion means to allowfluid to flow through at least one of said individual fluid conduitswhile causing said second occlusion means to prevent fluid flow intosaid receiving container and simultaneously causing said pressure meansto create a negative pressure in said chamber to precisely control theamount of fluid flow into said chamber, said control means furthercausing said first occlusion means to prevent fluid flow through all ofsaid individual fluid conduits after a predetermined amount of fluid hasbeen delivered to said chamber, said control means then further causingsaid second occlusion means to allow fluid to flow from said chamberthrough said outlet conduit while simultaneously causing said pressuremeans to create a positive pressure in said chamber to force fluid fromsaid chamber into said receiving container, said control meansincluding: source container indicating means for receiving sourcecontainer indicating signals from an operator of said device, saidsource container indicating signals indicating the particular ones ofsaid individual fluids to be transferred from said particular ones ofsaid source containers to said receiving container; and amountindicating means for receiving amount indicating signals from anoperator of said device, said amount indicating signals indicating theamount of each of said particular ones of said individual fluids to betransferred from said particular ones of said source containers to saidreceiving container; and means for operating said first and secondocclusion means for allowing fluid to flow from at least one of saidsource containers as indicated by said source container indicatingsignals into said chamber while preventing fluid to flow from saidchamber to said receiving container and means for preventing fluid fromflowing from said at least one of said source containers into saidchamber after the amount of fluid indicated by said amount indicatingsignals has entered said chamber as sensed by said sensing means thenallowing fluid to flow from said chamber said receiving container.
 34. Adevice for transferring multiple individual fluids from multiple sourcecontainers to a single receiving container, as recited in claim 33 saidcontrol means further comprising:means for causing said pressure meansto create a negative pressure in said chamber while allowing fluid toflow from at least one of said source containers, said negative pressurefor precisely controlling the amount of fluid transferred from saidsource containers to said chamber.
 35. A device for trnasferringmultiple individual fluids from multiple source containers to a singlereceiving container, as recited in claim 33 said control means furthercomprising:means for causing said pressure means to create a positivepressure in said chamber while allowing fluid to flow from said chamber,said positive pressure for enhancing flow of fluid from said chamber tosaid receiving container.
 36. A device for transferring multipleindividual fluids from multiple source containers to a single receivingcontainer, as recited in claim 34 said control means furthercomprising:means for causing said pressure means to creating a positivepressure in said chamber while allowing fluid to flow from said chamber,said positive pressure for enhancing flow of fluid from said chamber tosaid receiving container.
 37. A device for transferring multipleindividual fluids from multiple source containers to a single receivingcontainer, as recited in claim 33 said control means furthercomprising:means for operating said first and second occlusion means andsaid pressure means to cause fluid in said receiving container to besequentially withdrawn into said chamber and returned from said chamberback to said receiving container.
 38. A device for transferring multipleindividual fluids from multiple source containers to a single receivingcontainer, as recited in claim 37 wherein said pressure means creates anegative pressure in said chamber as said means for operating said firstand second occlusion means and said pressure means causes fluid in saidreceiving container to be sequentially withdrawn into said chamber andsaid pressure means creates a positive pressure in said chamber as saidfluid is returned from said chamber back to said receiving container.39. A device for accurately transferring multiple individual fluids frommultiple source containers to a single receiving container, in whichfluid flows from said multiple source containers through individualfluid conduits to a chamber having a single chamber fluid outlet conduitin fluid communication with the single receiving container, the chamberalso having a pressure conduit, the invention comprising:first occlusionmeans for selectively preventing fluid flow from each of said individualfluid conduits to said chamber; pressure means for selectively creatingpositive and negative pressures in said chamber to control the rate offluid flow through said chamber; second occlusion means for selectivelyoccluding fluid flow from said chamber outlet fluid conduit to saidreceiving container; hanger means for receiving and maintaining each ofsaid source containers during operation of the device; and control meansfor controlling said first and second occlusion means and said pressuremeans, said control means causing said first occlusion means to allowfluid to flow through at least one of said individual fluid conduitswhile causing said second occlusion means to prevent fluid flow intosaid receiving container and simultaneously causing said pressure meansto create a negative pressure in said chamber to precisely control theamount of fluid flow into said chamber, said control means furthercausing said first occlusion means to prevent fluid flow through all ofsaid individual fluid conduits after a predetermined amount of fluid hasbeen delivered to said chamber, said control means then further causingsaid second occlusion means to allow fluid to flow from said chamberthrough said outlet conduit while simultaneously causing said pressuremeans to create a positive pressure in said chamber to force fluid fromsaid chamber into said receiving container.
 40. A device as recited inclaim 39 wherein said hanger means further comprises:multiple pairs ofhooks, each pair of hooks for receiving a single source container, saidhooks including a first vertically extending portion and a secondperpendicularly extending portion, said second perpendicularly extendingportion connected to a lower end of said first vertically extendingportion.
 41. A device as recited in claim 40 wherein said hanger meansfurther comprises:means for maintaining each of said pairs of hooks in aparallel spaced apart relationship to one another.
 42. A device asrecited in claim 41 wherein said hanger means furthercomprises:adjustable spring means for providing a downward pressure oneach of said source containers to maintain said containers in a fixedposition during operation of the device.
 43. A device as recited inclaim 42 wherein said adjustable spring means means furthercomprises:torsion means for creating downward pressure on said sourcecontainer; spring hook attached to said spring means for contacting saidsource containers and for transmitting downward pressure from saidspring means to said source containers.
 44. A transfer set for use in anautomatic compounding device including a load cell and a differentialpressure source, said transfer set when in use providing selective fluidflow between a plurality of individual fluid source containers and asingle receiving container, said transfer set comprising:(a) a measuringchamber having a lower portion and an upper portion, said measuringchamber adapted to be suspended from said load cell; (b) a single fluidoutlet conduit attached to said lower portion of said measuring chamber,said single fluid outlet conduit providing selective fluid communicationbetween said measuring chamber and said single receiving container; (c)a manifold secured to said upper portion of said measuring chamber, saidmanifold having a plurality of connector conduits projecting therefromand providing fluid communication therethrough; (d) a plurality ofindividual fluid inlet conduits, each conduit having a first end, asecond end, and a soft occlusion portion, said second end of eachindividual fluid inlet conduits being attached to one of said pluralityof connector conduits of said manifold; (e) a plurality of individualspike being secured to said first end of said fluid inlet conduits, saidspikes when in use providing fluid communication between said individualfluid source containers and said fluid inlet conduits; and (f) apressure conduit having a first end and a second end, said first endbeing secured to one of said connector conduits projecting from saidmanifold, said second end adapted to be attached to said differentialpressure source of said automatic compounding device.
 45. The transferset recited in claim 44 wherein said manifold is releasably secured tosaid upper portion of said measuring chamber.
 46. The transfer setrecited in claim 45 further comprising:(g) means for providing afluid-tight seal between said manifold and said upper portion of saidmeasuring chamber.
 47. The transfer set recited in claim 46 whereinsaidfluid-tight sealing means comprises an O-ring.
 48. The transfer setrecited in claim 44 further comprising:(h) a tray having a mountingelbow with a plurality of parallel grooves therein, said plurality ofindividual fluid inlet conduits passing through said grooves in spacedupwardly-directed relationship, whereby in use mechanical stress effectson said measuring chamber and said load cell are significantly reduced.49. The transfer set recited in claim 48 wherein said tray furtherincludes a window, said soft occlusion portion of said individual fluidinlet conduits being within said window.
 50. The transfer set recited inclaim 44 wherein said plurality of individual fluid inlet conduitscomprise tubing made from a thermoplastic material.
 51. The transfer setrecited in claim 50 wherein said thermoplastic material is selected fromthe group consisting of polyvinyl chloride and polyethylene.
 52. Thetransfer set recited in claim 44 wherein said first end of saidindividual fluid inlet conduits is color-coded.
 53. The transfer setrecited in claim 45 wherein said spikes are vented.